Brushless DC motors are widely used nowadays due to a number of its advantages over brush-type motors. For example, the brushless DC motors use permanent magnets in the rotor, but electronically controlled windings in the stator, where the brushes which are subject to physical wear are eliminated and the lifespan of the motor can be greatly extended. Further, due to the electronic control of the stator windings by microcontrollers or other controlling units, the rotation of the brushless motor can be controlled in a more precise way, that desired speed of the motor can be achieved by serving precise control signals to the windings of the motor.
However, in conventional brushless motors there is usually only one set of windings in the stator connected to a motor controller, meaning that the motor is only capable of receiving one DC voltage from an external power supply. Therefore, the application of such brushless motors is limited in that the required single type power supply has to be configured at all time for proper operation of the motor.